1. Field of the Invention
This invention relates to the mounting of telephone dials in a telephone housing, and, in particular, to the mounting of these dials on the support structure of the telephone housing.
2. Description of the Prior Art
Telephone sets have advanced to the state where many interchangeable options fitting within the same basic housing may be provided to the customer when he selects a telephone set. Accordingly, the method of installing and removing these options has also changed due to the need for saving on time, ease of assembly, and expense.
Dial interchangeability in the telephone set has been one area of concern in which a simple but effective mounting technique that allows for the desired savings has not heretofore been obtained. This problem has persisted because of the structural difference between the standardized rotary and pushbutton dials that are being used in telephone sets. The respective heights and widths of the two dials differ and unfortunately, their attachment points do also, making difficult the use of a common support structure that the two dials could attach directly thereto.
In an effort to overcome this dial mounting problem one prior arrangement disclosed in U.S. Pat. No. 3,838,232 issued Sept. 24, 1974 to R. Morrell et al., shows a dial mounting technique whereby either the rotary or the pushbutton dial is mounted in a telephone housing by using a single pair of upstanding brackets secured to the base of the housing a fixed distance apart. The brackets have offset wall portions such that in one related opposed position mounting for the rotary dial is provided, while when the positions of the brackets are reversed, mounting for the pushbutton dial is provided. The offset wall portions have multiple screw-receiving slots formed therein to accommodate the difference in heights between the two dials.
In order to facilitate the mounting and removal of the brackets, the base of the telephone housing includes a pair of bracket-receiving, fixed channel members that are permanently secured thereto. Each channel member has an anchorage at one end and a short flexible retaining member at the other end. Each one of the upstanding brackets is engaged to a channel member by inserting a slot on one edge into the anchorage and then rotating the bracket to snap a tab at the opposite edge under the retaining member.
This arrangement permits the use of just two distinct brackets to mount both the rotary and pushbutton dials but at the same time creates the need to take precautionary measures during the mounting operation so as to insure that the support brackets are installed correctly. Interchanging of the dials would thus appear to be a fairly involved procedure and requires a degree of care that can be prone to error. If, for example, it becomes necessary to replace a dial in the field using the foregoing arrangement, other components within the housing would have to be removed in order to obtain the necessary space to reach under the dial and deflect the retaining member so as to free the brackets. Once the support brackets and dial are removed from the housing as an assembly, the brackets are unscrewed from the dial, their positions interchanged, and then they are refastened to a new dial. Care must be taken to insure that the brackets are oriented in the right direction for mounting in the support channel and that the correct screwreceiving slot in the bracket is used for the dial to be mounted. After the brackets with the dial attached thereto have been mounted in place on the base of the telephone housing, the components that were first removed to provide access are then remounted. Thus from the foregoing, it is seen that while the Morrell and other arrangements may facilitate initial assembly at the factory, they do not facilitate replacement of the dial in the field.